The Ranking System

The Ranking System

Initially the BDA will use the ELO Model to calculate the National Ranking points for BDA Member clubs.

The ELO Model

Elo modelling is a commonly-used approach towards creating ranking systems in sport originally derived for chess. It is used across multiple sports at international level including golf, tennis and snow-boarding.

The principle is that points are awarded for each event based on your previous ranking and the difference between you and the teams you beat.

β€’ If a lower ranked team (A) beats a higher ranked team (B), team A is rewarded a lot because they were expected to lose, but won. Likewise, team B loses points because they were expected to win, but lost.

β€’ If a lower ranked team (A) loses to a higher ranked team (B), team A loses less points because they were expected to lose and lost. Team B should not be rewarded much because they were expected to win and won.

This prevents higher ranking teams continually racing lower ranking teams just to gain β€˜easy’ points.

The main purpose of this is to rank the teams from highest to lowest performing and not to award points, however to get a ranking points are calculated in accordance with the following equations.

Most people can stop reading now!

For the mathematically minded here is the detail

RW = Elo rating of wining boat,

RL = Elo rating of losing boat,

EW = Expected points of boat 1 = 1 1+10(π‘…πΏβˆ’π‘…π‘Š)/400 EL = Expected points of losing = 1 1+10(π‘…π‘Šβˆ’π‘…πΏ)/400

and K (The k factor),also referred to as the rate of change, a parameter defined for each event.

The winning boat’s new rating calculated as: RW + K*(1 – EW)

The losing boat’s new rating is calculated as: RL + K*(0 – EL)

For multiple boats in an event we are implementing a multi-elo model. We are using initial parameters of k = 32 and d = 400 based on initial running of the 2019 models. If anyone has any expertise in this area we would love to hear from you